The proposed work is designed to study amino acid metabolism, with reference to turnover, oxidation and incorporation into serum proteins in patients who have progressive cancer with weigh loss. The technique would be the administration of 14C labelled amino acids with determination of radioactivity in the amino acid given, other amino acids, glucose, CO2 of expired air and serum proteins. The data analysis involves renewal theory and circulating flow rates. The purpose of the study is to determine whether change in amino acid catabolism and rate of synthesis into serum protein exists in this group of patients.